There are many mechanical writing instruments having retractable marking ends currently in commercial production. However, the writing instruments are designed to provide a writing member having a writing end with a fixed relation with the end of the holding portion of the writing instrument. However, the fixed relationship between the marking end of the writing member and the end of the holding member is inconvenient in some circumstances such as drawing a line along the edge of a ruler or for persons who use the writing instrument with a particular slant in their holding thereof. It would therefore be useful to provide a writing instrument with a retractable writing member having a marking end which could be positioned at different relationships between the end of the holding member and the marking end of the writing member.